setClass("ExternalClusterScore",contains="ClusterScore",
		representation(
				"VIRTUAL"
		),
		prototype=prototype(
				.description="Virtual Cluster Internal Score class"
		
		)
)  

#global functions
#methods
setMethod("ScoreSet",
		signature="ExternalClusterScore",
		definition=function(.Object,inputSet,clusters,...){
			#check for X element and clusters
			callNextMethod(.Object,inputSet,clusters,...)
			
			#check for Y element
			Ycheck(inputSet)
			
			
			return(0.0)
		}
) 

